1. Technical Field
The present invention pertains to systems for heating medical items. In particular, the present invention pertains to a system for heating and maintaining medical solution containers (e.g., bags or bottles containing saline or intravenous (IV) solutions, antibiotics or other drugs, blood, etc.) or other medical items (e.g., instruments, blankets, etc.) at desired temperatures.
2. Discussion of Related Art
Generally, various items are required to be heated prior to utilization in a medical procedure to prevent thermal shock and injury to a patient. These items typically include intravenous solution, surgical instruments, bottles and blankets. In order to provide the necessary heated items for use in medical procedures, medical personnel may utilize several types of warming systems to heat items toward their operational temperatures. For example, ovens may be disposed within operating rooms to heat items to desired temperatures. Further, U.S. Pat. No. 4,495,402 (Burdick et al) discloses a warmer for heating wet dressings and other articles disposed within a heating and storage compartment. The articles are arranged within the compartment in stacked relation and disposed on a plate that is supplied with thermal energy from a heater. The plate includes a center aperture whereby a first thermal sensor is disposed in the aperture in contact with a bottommost article. Control circuitry is disposed beneath the plate to control the heater to maintain temperature of the bottommost article at a desired level based on the temperatures sensed by the first thermal sensor and a second thermal sensor responsive to heater temperature.
U.S. Pat. No. 5,408,576 (Bishop) discloses an intravenous fluid warmer having a cabinet structure to accommodate a plurality of intravenous fluid bags. A temperature sensor and pad of heating filaments are disposed within the cabinet structure, whereby the temperature sensor enables automatic temperature regulation of the pad of heating filaments to heat the intravenous fluid bags. The heating filaments are covered by a rubber layer to prevent melting of the bags during heating. A temperature indicator disposed on the cabinet structure permits a user to ascertain when a desired temperature is attained, whereby an intravenous fluid bag is removed from the intravenous fluid warmer via an opening defined in a side of the cabinet structure.
The warming systems described above suffer from several disadvantages. In particular, ovens typically do not have a high degree of accuracy or control, thereby enabling use of items having temperatures incompatible with a medical procedure and possibly causing injury to a patient. Further, the Burdick et al and Bishop warmers employ heaters that generally contact a particular portion of an article being heated, thereby heating articles in an uneven manner and enabling formation of hot spots. Moreover, the Burdick et al and Bishop warming systems heat items simultaneously to only a single desired temperature, thereby being incompatible for applications requiring various items to be heated to different temperature ranges.
The present invention overcomes the aforementioned problems and provides several advantages. For example, the present invention evenly distributes heat among intravenous solution bags or other medical items contained within system drawer sub-compartments, thereby avoiding creation of "hot spots" and "cold spots" and ensuring relatively uniform heating of the entire bag with enhanced temperature control. Further, each system drawer includes a window to enable viewing of the intravenous solution bags or other medical items during heating, while the system drawers facilitate easy access to the medical items within the system. In addition, the present invention incurs low operating costs, while providing versatility since the system drawers are each individually controlled to enable the system to heat intravenous solution bags or various other medical items to the same or different desired temperatures.